Portion of a buffet



FIG. 1 is a front view of a portion of a buffet of my new design;

FIG. 2 is a left-side view thereof, the right-side view being identical thereto; and

FIG. 3 is a top view thereof.

The broken lines, showing a lower portion of the buffet, are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a portion of a buffet, as shown and described. 